Continuous phase composite for musculoskeletal repair

ABSTRACT

A composite material for positioning in the anatomy to form a selected function therein. The composite may be resorbable over a selected period of time. The composite may allow for selected bone ingrowth as absorption of the composite occurs.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/017,992, filed on Jan. 31, 2011, which is a divisional of U.S. patentapplication Ser. No. 11/008,075, filed on Dec. 9, 2004, now U.S. Pat.No. 7,879,109, issued Feb. 1, 2011, which claims the benefit of U.S.Provisional Application 60/634,448, filed on Dec. 8, 2004. Thedisclosures of the above applications are incorporated herein byreference.

BACKGROUND

The present teachings relate generally to materials useful inorthopaedic surgery, including orthopaedic implants composed ofresorbable materials.

In general, the human musculoskeletal system is composed of a variety oftissues including bone, ligaments, cartilage, muscle, and tendons.Tissue damage or deformity stemming from trauma, pathologicaldegeneration, or congenital conditions often necessitates surgicalintervention to restore function. During these procedures, surgeons canuse orthopaedic implants to restore function to the site and facilitatethe natural healing process.

Current orthopaedic implants are generally composed of non-resorbablemetals, ceramics, polymers, and composites. However, in some instances,it may be desirable to have an implant made of resorbable material.These bioresorbable or biodegradable materials are characterized by theability to be chemically broken down into harmless by-products that aremetabolized or excreted by the body. Materials of this type can offer anadvantage over conventional non-resorbable implant materials.Bioresorbable implants provide their required function until the tissueis healed, and once their role is complete, the implant is resorbed bythe body. The end result is healthy tissue with no signs that an implantwas ever present.

Bioresorbable materials are substances well known in the art. Thisincludes resorbable polymers such as poly(lactic acid) [PLA] andpoly(glycolic acid) [PGA], and ceramics such as hydroxyapatite,tricalcium phosphate, and calcium carbonate. Additionally,polymer/ceramic composites have also been used as an implant material.Overall, these materials have been used to fabricate a large range oforthopaedic implants including screws, plates, pins, rods, spacers, andthe like. Clinically, these devices have a long history of use thatspans a wide variety of surgical procedures. Resorbable devices havebeen used in applications such as fracture fixation, bone grafting,spinal fusion, soft tissue repair, and deformity correction.

SUMMARY

A composite material for positioning in the anatomy to perform aselected function therein is disclosed. The composite may be resorbableover a selected period of time. The composite may allow for selectedbone ingrowth as absorption of the composite occurs. Also, the compositemay include a first material of a first resorption profile and a secondmaterial of a second resorption profile.

According to various embodiments an implantable resorbable material isdisclosed. The material can include a first material operable to beresorbed into an anatomy at a first resorption rate and defining aplurality of pores. A second material operable to be resorbed into theanatomy at a second resorption rate can be positioned relative to thefirst material to substantially fill at least a sub-plurality of theplurality of the pores. The first resorption rate of the first materialcan be different than the second resorption rate of the second material.

According to various embodiments a method of forming a resorbableimplant is disclosed. The method can include selecting a first materialincluding a first resorption rate and selecting a second material havinga second resorption rate. A porous structure of the first material canbe provided and a composite can be formed with the first material andthe second material. The composite can be formed by substantiallyfilling at least a sub-plurality of the plurality of the pores with thesecond material. An implant can be formed of the composite. Theresorption rate of the first material is different than the resorptionrate of the second material to allow a bone ingrowth after implantationof the implant.

According to various embodiments a method of forming a resorbableimplant is disclosed. The method may include selecting a region of theanatomy to position an implant. In the region of the anatomy selected aforce produced, a bone regrowth rate, a length of time that the implantshould retain a selected strength, or other properties can bedetermined. A resorption rate of at least a portion of the implant afterimplantation can also be determined. A first material can be selecteddepending at least upon the determined resorption rate. Also, a secondmaterial can be selected depending upon at least one of the determinedbone regrowth rate, the determined force in the region of the anatomy,the determined length of time that the implant should retain a selectedstrength, or combinations thereof. An implant can be formed of the firstmaterial and the second material.

The composite implant materials provide the ability to allow tissueingrowth into the implant, improved degradation profiles, improvedstrength retention, elimination of long term degradation complications,and improved biocompatibility with surrounding tissues. Furtheradvantages and areas of applicability of the present teachings willbecome apparent from the detailed description provided hereinafter. Itshould be understood that the detailed description and various describedembodiments are intended for purposes of illustration only and are notintended to limit the scope of the teachings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present teachings will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a perspective view of an environmental view of an implantaccording to various embodiments;

FIG. 2 is a perspective detailed view of a scaffold according to variousembodiments;

FIG. 3 is a perspective detailed view of a continuous phase compositeaccording to various embodiments of the invention;

FIG. 4 is a graph showing compressive strength over time of a continuousphase composite and a pure polymer specimen;

FIG. 5A shows tissue ingrowth into an implant according to variousembodiments placed in an in vivo bone defect at 3 months;

FIG. 5B shows tissue ingrowth into an implant according to variousembodiments placed in an in vivo bone defect at 9 months;

FIG. 5C shows tissue ingrowth into an implant according to variousembodiments placed in an in vivo bone defect at 18 months;

FIG. 6 is a detailed view of the replacement of a large portion of thecontinuous phase composite with normal bone at 18 months;

FIG. 7 is an implant according to various embodiments;

FIG. 8 is an implant according to various embodiments;

FIG. 9 is a perspective view of an implant according to variousembodiments;

FIG. 10A is a plan view of an implant according to various embodiments;

FIG. 10B is a perspective view of an implant according to variousembodiments illustrated in FIG. 10A;

FIG. 11 is a perspective view of an implant according to variousembodiments;

FIG. 12 is a perspective view of an implant according to variousembodiments;

FIG. 13 is a perspective view of an implant according to variousembodiments;

FIG. 14 is a plan view of an implant according to various embodiments;

FIG. 15 is a plan view of an implant according to various embodiments;

FIG. 16 is a perspective view of an implant according to variousembodiments;

FIG. 17 is a perspective environmental view of the implant in ananatomy;

FIG. 18 is a perspective view of an implant according to variousembodiments;

FIG. 19 is a flow chart of a method of forming an implant according tovarious embodiments; and

FIG. 20 is a flow chart of a method of forming an implant according tovarious embodiments.

DESCRIPTION OF THE VARIOUS EMBODIMENTS

The following description of various embodiments is merely exemplary innature and is in no way intended to limit the teachings, itsapplication, or uses. Although the following various examples may relateto spinal implants, fracture plates, anchors, screws, or the like, otherappropriate implants may be formed. Also, although various materials aredisclosed for use in various applications, it will be understood thatother appropriate materials may also be provided.

An implant 100 (FIG. 9), as illustrated in FIG. 1, may be positionedrelative to a selected portion of an anatomy. Various appropriateanatomies include those of a human and may include the cervical spine 2and a skull 3 of a human. The implant 100 may be a spacer for use in aspinal fusion procedure, as discussed herein. Thus the implant 100 maybe positioned between a first vertebrae 2 a and a second vertebrae 2 b.Although the implant 100 may be used in a spinal procedure, it will beunderstood that implants according to various embodiments may be formedand used in selected procedures.

With reference to FIG. 2, a structure 10 is illustrated. Although thestructure 10 may be any appropriate material, it is exemplary a ceramicmaterial such as Pro Osteon 500R. The structure 10 can also be referredto as a scaffold. The scaffold may be used for various purposes, such assupporting or encouraging bone ingrowth when used in an implant. Thestructure 10 can also be a polymer matrix, or any other appropriatematerial. The structure 10 can include any appropriate materials, suchas biocompatible, bioabsorbable, or any appropriate material. Forexample, the structure 10 can be formed of a ceramic and generallyinclude a substrate comprising calcium carbonate 12 that is coated witha thin layer of hydroxyapatite 14.

The structure 10 may be formed of natural sources of biocompatible,bioresorbable materials, such as coral. Alternatively, or in additionthereto, various synthetic materials may be used to form the structure10. These materials may include absorbable ceramics, absorbablepolymers, or any other absorbable porous matrix. In various embodiments,the porous material may include the resorbable ceramic sold under thetrade name Pro Osteon 500R by Interpore Spine Ltd. (Irvine, Calif.,U.S.A.), Calcigen PSI by Biomet (Warsaw, Ind., USA), or OsteoStim by EBI(Parsippanny, N.J., USA). Porous materials useful herein include thosedisclosed in U.S. Pat. No. 4,976,736, White et al., issued Dec. 11,1990; and U.S. Pat. No. 6,376,573 White et al, issued Apr. 23, 2002,which are hereby incorporated by reference.

The Pro Osteon 500R material consists of an interconnected or continuousporous calcium carbonate substrate with a thin surface layer ofhydroxyapatite. Various other exemplary porous materials may includecalcium carbonate, tricalcium phosphate, biphasic calcium phosphate, orany appropriate calcium based ceramic. It will also be understood thatthe structure 10 may be any appropriate combination and may be formed inany appropriate combination, such as including one material as a coatingon another.

Also the structure 10 may be formed from a polymer. A polymer matrix maydefine a porous structure similar to the structure 10. The material ofthe polymer matrix may be any appropriate polymer such as abiocompatible, resorbable polymer including those discussed herein.Thus, it will be understood, that the structure 10 may be formed of anyappropriate material, including a biocompatible, resorbable ceramic,polymer, composite, etc.

The structure 10 itself may be used for various purposes, such as a boneregeneration scaffold or bone graft replacement. Nevertheless, thephysical properties of the structure 10 can be augmented for variousreasons. For example, the structure 10 alone may not include a selectedphysical property, such as a selected compressive strength, tensilestrength, torsion strength or the like. Thus, the structure 10 may beaugmented to improve its properties allowing for greater use as asurgical device, as discussed herein in various embodiments.

To augment the structure 10, a second material may be added thereto,such as during formation of the structure 10 itself or at a later time.For example, a selected material may be injected into or otherwiseprovided into a pore 16 defined by the structure 10. The structure 10can include a channel or plurality of pores 16 that may be asubstantially continuous or interconnected pores. The pores 16 maydefine a plurality of sizes of pores or porous structures. For example,the pores may range from about 0.1 nanometers (nm) to about 1 mm.

The pores 16 define a generally interconnected path or connectionthroughout the structure 10. Paths or channels can interconnect thepores 16. The interconnected nature of the pores 16 may be referred toas a continuous phase throughout the structure 10 as well. Thecontinuous phase may also be understood to be interconnected pores thatare defined by a solid portion of the structure 10. Thus, the channels16 of the structure 10 are defined by the structure 10 and extendthroughout the structure 10. Moreover, the channels 16 generally extendthrough the structure 10 such that a path can be traced from a firstside 10 a of the structure 10 to a second side 10 b of the structure 10or from an entrance path to an exit path that can enter and exit fromany sides or from the same side.

The pores 16 may be connected with other channels 16 to form theinterconnected or continuous pores or channels. Also the variouschannels may interconnect such that more than a single channel or twoopenings may be interconnected in the structure 10. It will beunderstood, however, that the pores 16 may be any opening that allowsaccess to the interior of the structure 10. For example there may beinterstitial spaces defined between the portions that define thechannels interconnecting other pores. These interstice spaces may alsobe referred to as pores. Therefore, it will be understood that the pores16 may be any opening that allows access to the interior of thestructure 10 and may be filled with a second material, as discussedherein.

The different sized pores or channels may be used with or arespecifically applicable to different types of surgical indications. Forexample, with reference to FIG. 3, the macropores, such as thosegenerally ranging from about 10 um to about 1 mm, may be filled with aselected polymer 21. If desired, the microporosity, generally in therange of about 0.01 μm to about 1 μm, can be left open and substantiallyfree from any material. The polymer 21 may be injection molded in asemi-liquid, molten form to fill the macroporosity defined by thestructure 10, such as the pore sizes that are operable or easily filledwith the polymer in a flowable state. Various polymers may be used tofill a selected porosity of the structure 10. For example,bioabsorbable, biocompatible, or any appropriate combination ofmaterials may be used.

It will also be understood that any appropriate number of materials maybe provided. Therefore, not only the structure 10 and a polymer 21 maybe used. For example, various materials also include those that includetherapeutic aspects, such as antimicrobial agents that can be released.Nevertheless, the structure 10 may be filled to any appropriate degreewith more than one material.

In addition, the selected polymer 21 may include polylactic acid. Forexample, a polylactic acid may be provided that includes compositionalratio of about 70:30 poly(L/D,L lactic acid). The specific ratio ofvarious chiral monomers in the polymer is merely exemplary and anyappropriate ratio may be used. Nevertheless, herein the 70:30 (L/D,Llactic acid) may be referred to as PLDLLA. Other polymers may include acopolymer of lactic acid and glycolic acid. It will be understood,however, that any appropriate polymer material may be used to form thecomposite 20. Other bioresorbable, biocompatible polymers includepoly(glycolic acid), poly(carbonate), poly(urethane), poly(amino acids),poly(phosphazenes), poly(hydoxyacids), poly(an hydrides),poly(dioxanone), poly(hydroxybutyrate), poly(caprolactone). Alsocopolymers of these or other appropriate monomers may be used. Further,as discussed above, the structure 10 may be formed of a matrix includingthese polymers or copolymers.

The selected polymer that may be used with the structure 10, however,may be injection molded or otherwise fill the pores defined by thestructure 10. The polymer 21 may fill the pores of the structure 10 toform a substantially solid structure. Nevertheless, the composite 20 maystill include a selected porosity or open channels even when filled withthe polymer 21. Also, it may be selected to fill the pores 16 less thancompletely, therefore leaving an open space in at least a portion of thepores even if they may include some of the fill material. For example,pores having a size of about 0.01 μm to about 10 μm may still remain inthe composite 20 after the polymer is injected or fills the larger poresor macro pores of the structure 10. The pores that are generally lessthan about 10 μm, may be herein referred to as micropores ormicroporosity. The microporosity, however, is not necessary and may notalways be present. For example, with various polymer filling techniques,such as polymerization of a positioned monomer, discussed herein, themicroporosity may be substantially less or non-existent in the compositematerial 20. As is generally understood a polymer is generally formed ofa single monomer while a copolymer generally includes at least two typesof monomers.

The composite material 20 may also be formed with any other appropriatemethod. Generally the polymer used to fill the selected porosity isadded to the structure 10 or otherwise used to fill the porosity of thestructure 10. In one embodiment, injection molding is used to forcemolten polymer into the macroporosity of a porous ceramic structure 10.This can result in the composite material 20 including approximately5-10% open microporosity. In addition, vacuum impregnation techniquesmay be used. In this instance rather than producing a positive pressureon the melted polymer, a relatively low pressure is formed in thestructure 10 to pull the polymer 21 into the porosity. Furthertechniques, include solution embedding where the polymer 21 is dissolvedand then cast into the porosity.

Also, in situ polymerization techniques where the polymer may bepolymerized within the porosity of the structure 10 can be used to formthe composite 20. In this embodiment, the structure 10 is submerged in areaction mixture of a monomer or plurality of monomers, an initiator,and/or a catalyst and then heated to the reaction temperature. Thepolymer is then formed in situ within the porosity of the structure 10.

According to various embodiments, the composite 20 can include a dualceramic. The structure 10 can be formed of a first ceramic including afirst property and the channels or pores may be filled with a secondceramic, rather than the polymer 21, including a second property. Thedifferent properties can include resorption rates, compressivestrengths, torsion strengths, or the like. This can be achieved bycasting a ceramic slurry into the porosity of the structure 10. Theslurry can undergo a chemical reaction to set into a hardened form or itcan be sintered to form a rigid ceramic phase.

Other methods of forming the composite material 20 are related to theuse of porous polymer matrices as the structure 10. The ceramic materialis cast within a porous, polymer matrix structure that forms thestructure 10. A polymer matrix may be formed to include a selectedporosity and a ceramic slurry may be positioned in the pores of thematrix. The slurry may then be forced to harden to form a solid orporous ceramic phase within the porosity of the polymer structure 10.Thus, the composite 20 may be formed by positioning the polymer in thestructure 10 formed of a porous ceramic or by positioning a ceramic inthe structure 10 formed of a porous polymer.

Also, two polymers including different properties can be used to formthe composite 20. A first polymer including a first property may be usedto form the structure 10 that includes a selected porosity and/orchannels. The porosity of the structure 10 can be filled with anotherpolymer with a different property. Again, the properties of the twopolymers may include a compressive strength, a resorption rate, atensile strength, or the like. This can be achieved through injectionmolding, in situ polymerization, and solution casting techniques.

It will be understood that the composite 20 may be a substantially dualphase or greater composite so that it will react in substantiallyuniform manner when implanted in the body. The phases can refer to thephase of the structure 10 and the phase of the material positioned inthe channels 16 of the structure 10, such as the polymer 21. Accordingto various embodiments, the composite 20 may be about 30 weight percent(wt %) to about 70 wt % polymer fill 21 and about 30 wt % to about 70 wt% structure 10. For example, the composite material 20 may be about 55wt % to about 65 wt % polymer fill 21 and about 45 wt % to about 55 wt %ceramic structure 10. Nevertheless, the composite 20 may besubstantially 100 wt % polymer if the structure 10 is formed from aporous polymer matrix. In this case the composite 20 may be about 30weight percent (wt %) to about 70 wt % polymer fill and about 30 wt % toabout 70 wt % porous polymer matrix. The same applies to a substantially100% ceramic composite composed of a slow and fast resorbing ceramic.

Both phases, that being the structure phase 10 and the fill phase 21 maybe substantially continuous. This means, according to variousembodiments, that the fill portion 21 is substantially interconnectedthroughout the composite 20 and that structure phase 10 is alsosubstantially interconnected. This can be a result of using an intactstructure phase 10 rather than a particle. Though, it will beunderstood, that an appropriate structure phase 10 may be formed fromparticles. By filling the porosity of the structure phase 10 with asecond material 21, the resulting composite 20 is effectively composedof two or more distinct, intact, and continuous phases. As discussedherein, the different resorption rates of the continuous phases 10, 21within the composite 20 results in a resorption profile that can includea slowly degrading phase and a quickly degrading phase. The quicklydegrading phase can allow for tissue ingrowth as the phase is resorbedwhereas the slowly degrading phase provides the implant site withmechanical support. It will be understood that either the structure 10or the fill 21 may be formed to be the quicker resorbing phase.

The composite 20 is the result of filling the macroporosity of structure10. However, the microporosity of the structure 10 can be left open.This microporosity found in the ceramic phase of composite 20 may,without being bound by the theory, function in that it allows for theabsorption of fluid throughout the composite 20 and the diffusion ofdegradation products out of the composite. This allows the composite 20to degrade in an even manner from the inside out, results in a gradualtransition of load to the newly regenerating tissue. In instances whereacid based polymers such as poly(lactic acid) and poly (glycolic acid)are used as the fill phase within the composite, the microporosity inthe ceramic allows the acidic products to leave the implant and beabsorbed by the surrounding tissue in a timely manner.

As discussed above, the polymer injected into the structure 10 may fillthe macroporosity of the matrix 10 but maintain an open microporosity.The effect of this microporosity and/or continuous phase aspects of thecomposite on the degradation of a continuous phase composite 20 is shownin FIG. 4. The graph in FIG. 4 illustrates the results of an experimentwhere degradation was conducted in a generally known phosphate buffersolution held at about body temperature (about 37° C.). The degradationprofile of a continuous phase composite composed of PLDLLA and ProOsteon 500R was compared to a pure polymer sample composed of onlyPLDLLA. In FIG. 4, the graph of compressive strength over time shows agenerally even and linear degradation profile of the composite (line 30)when compared to faster drop in strength seen with the pure polymerdevice (line 32). Although the same polymer was used in both thecomposite and pure polymer specimens, the graph clearly shows the impactof the composite 20.

As illustrated in FIG. 4, the compressive strength of the pure PLDLLAsample does not change over a significant life span of the implant.Nevertheless, after about 150 days, a drop in compressive strength isillustrated. Therefore, during a majority of the life span of the PLDLLAimplant, the compressive strength does not change while near the end ofits life span, the compressive strength may degrade rapidly. The moreeven and linear drop in strength may be selected for variousapplications. This may allow for an even and gradual loading of an areaof the anatomy near the implant of the composite 20.

Examining the composite degradation profile, as illustrated by line 32,the compressive strength of the composite material 20 is substantiallylinear over its lifetime. That is, that the degradation of thecompressive strength of the composite 20 does not include any longperiods of maintenance of a single strength, nor a steep drop off at anyparticular time. A substantially linear decrease in compressive strengthover time in the degradative environment, such as an anatomicalenvironment, allows for the gradual loading of healing tissue withadditional stresses.

For example, when the implant is used as a bone replacement, it may bedesirable to have a substantially continuous increase in stressesrelative to the implant. As is known to one skilled in the art, theincrease of stresses relative to the bone may increase or enhance boneingrowth into the area. Particularly, in a resorbable implant, it isdesirable to increase or enhance bone ingrowth into the area where theimplant has been degraded. As the implant degrades, the stresses aretransferred to the surrounding bone, and the new tissue slowly becomesload bearing.

In various embodiments, the composite material 20 has exhibited a lineardecrease in strength as shown FIG. 4. In addition to the benefits of agradual transfer of forces to the new tissue, the continuous phasecomposite also demonstrates superior for tissue ingrowth into theimplant. This ability was demonstrated in a load bearing bone defectmodel in the tibia and femur of sheep. In such a model, typical solidpolymer implants may show bone formation in limited amounts on thesurface of the material. With the continuous phase composite 20, theresorption of the ceramic phase allowed eventual bone into the center ofthe implant wall. In this study a generic implant cage was fabricatedwith a central area designed to hold bone graft materials and wasimplanted into the tibia and femur of sheep. The implant 52 generallyincluded Pro Osteon 500R formed into a composite with PLDLLA. As seen inFIG. 5A-5C, back scattered electron microscope images demonstrated thegradual penetration of bone into the implant from 3 to 18 months.

With reference to FIG. 5A, the outer edge of the implant 52 isillustrated by phantom line 50. This 3 month image shows a continuouslayer of bone 54 covering the entire implant surface and additional bone56 penetrating approximately 300 um into the implant material 52. Thepenetration of bone within the device 50 can be the result of resorptionof the structure phase 10 of material 52, which allowed bone ingrowthinto various spots shown in 56.

As illustrated in FIG. 5B, at about 9 months, the implant material issubstantially more degraded and large amounts of bone ingrowth are seen.As illustrated in FIG. 5B, bone, particularly new bone 54A, has growndeep into the implant area 50. The new bone growth 54A is substantiallynext to and intermixed with the ceramic structure 10 of the compositematerial. Further, portions of the polymer material 58 are beingdegraded as well.

With reference to FIG. 5C, the implant 50 is quite degraded in vivoafter about 18 months. Again, the new growth bone material 54A isgrowing deep into the implant area. Even further, it is growingsubstantially next to or adjacent various portions of the constructmaterial 10, while the polymer material 58 is also being activelydegraded.

FIG. 6 shows a further example of the 18 month degradation response.This image shows new bone growth 54A occurring substantially adjacent tothe original implant material, including the structure 10. Thisindicates that significant portions of the polymer 58 have been replacedby bone. The image clearly shows new bone growth 54A in areas oncefilled with polymer indicating the lack of any implant complications.

Further, the image in FIG. 6 shows portions of bone 54A intermixed withareas of residual ceramic matrix 10. In this exemplary embodimentincluding Pro Osteon 500R as the structure 10, the residual portions ofceramic structure 10 are substantially composed of calcium carbonate.The interaction of calcium carbonate and lactic acid from the polymerphase 58 results in a self-neutralizing reaction that eliminates some ofthe acid released from the degrading implant. This phenomenon furtherimproves the long term biocompatibility of the device as seen by boneformation in areas of active lactic acid degradation.

In addition to the self-neutralizing ability of the composite, thepresence of vascularized bone and residual microporosity also add to theoverall biocompatibility of the degrading composite. This tissue andpore system serves as a means to transport degradation products from thesite to the bloodstream. The blood vessels within the implant and themicroporosity system allow degradation by-products to be cleared fromthe implant area in a timely manner.

With reference to FIG. 7, an implant 70 is illustrated. The implant 70demonstrates the versatility of the fabrication process by machiningdevices with both a composite region 74 and a polymer region 76. Forexample, the implant 70 may include an external thread or engagementportion 72 composed of the continuous phase composite 74 similar to thecomposite 20. However, implant 70, can be machined from a compositeblock with an excess polymer region. This results in a dual regionimplant with a polymer head 76 and a composite base 74. Therefore, thecomposite portion 74 may be formed from a ceramic material, such as thePro Osteon 500R, that has been reinforced or injected with a polymer,such as the PLDLLA. Also, the polymer portion 76 may be molded to thecomposite portion 74 according to various embodiments.

In addition, the polymer portion 76 may be composed of 100% PLDLLA. Suchan implant can improve the mechanical properties of the device forvarious applications. For example, the second portion 76 including onlythe polymer region, may provide a torsional strength that is greaterthan the torsional strength of the composite portion 74. Therefore, atool engaging portion or area 78 may be formed in the polymer portion 76to allow for a greater torsional force to be applied to the implant 70that may not be satisfied by the composite portion 74.

With reference to FIG. 8, an implant 90 may be provided for similarpurposes. The implant 90 can also include two portions, such as acomposite portion 92 and a polymer portion 94. The composite portion 92may be substantially similar to the composite material 20 illustrated inFIG. 3. The addition of the polymer portion 94 to the central area ofthe composite portion 92, however, can be used to achieve selectedproperties of the implant 90.

With regard to the fabrication of implant 90, this orientation ofpolymer 94 and composite 92 can be fabricated by drilling holes withinthe porous structure 10 and then subjecting the structure 10 to one ofthe composite fabrication techniques. The addition of the polymer phase21 to the structure 10 with holes, such as through injection molding,results in filling of the holes in addition to creating the composite.During the machining of the implant, the device 90 can be centeredaround the central polymer region 94 to define a bore 96 through theimplant 70. The resulting implant will have a central polymer bore 94surrounded by a composite region 92.

The implant 90 may be used for any appropriate purpose, and anengagement portion 98 may be formed on an exterior thereof. Theengagement portion 98 may be used to engage various structures, such asbony portions, such that the implant 90 may be an anchor or may define ascrew. Further, a tool engaging structure 100 may be defined in thepolymer portion 94 for allowing engagement of a tool with the implant 90for positioning the implant 90 in various anatomical locations. Asdiscussed above, the implant 90 may be used for various purposes,similar to the purposes for the implant 70. Therefore, the implant 90may be used as a bone anchor, a suture anchor, a soft tissue anchor,fracture screw, or any appropriate portion. Further, the implant 90 maybe used for any other appropriate procedure or implant.

Implants, such as the implants 70, 90 according to various embodimentsmay be formed in many different ways and include different structures.Those described above are merely exemplary in nature and not intended tolimit the teachings herein. For example, an implant 70,90 may include anexterior “thin” coat formed around a polymer interior, or vice versa.The thin coat may include a thickness that is substantially less thanthat of the interior portion, but provide selected properties to theimplant. That is, the implant may be formed in any appropriate mannerand for various purposes. Also a portion of the polymer may be placed asa seam or flex point in an implant with the composite or other materialsurrounding it.

Various other types of implants include sheets formed of the composite20, for example implants that include a surface area greater than athickness. Additionally, reinforcing ribs or struts composed of polymercan be added to the composite device in order to provide an improvementto the required mechanical properties. Also, tacks, bone fusion devices,bone graft devices, cement restrictors, intramedullary pins, and otherimplants may be formed from combinations of the composite 20 and polymerregions. Thus, one will understand that the implants described hereinare merely exemplary.

With reference to FIG. 9, a spinal implant 100 is illustrated. It willbe understood that the implants, according to various embodiments, maybe positioned between any appropriate vertebrae. Therefore, discussionof a first vertebrae and a second vertebrae is not necessarily C1 and C2or any other specific set of vertebrae, unless do discussed. The spinalimplant 100 may be for any appropriate spinal application, such as anintervertebral spacer for cervical fusion. The cervical spine implant100 may include a ring or open structure including an exterior wall 102and an interior void 104. The interior void 104 may be defined by aninterior wall 106. The purpose of the interior void can be to containbone graft materials such as autograft, or allograft.

Additionally, the structure 10 can act as a bone growth scaffold it canalso be added to the void 104. This would result in an implant includinga central portion of the structure 10 and the composite 20 surroundingit. This would allow the composite 20 to support the surgical site whilethe graft or structure material 10 can allow for immediate ingrowth.

The cervical spine implant 100 may be formed in any appropriate manner.For example, a block of material formed of the composite 20 may bemachined into a shape of the implant 100. Alternatively, the materialforming the structure 10 can be machined into the cervical spine implant100 shape and then filled with the polymer material to create thecomposite 20. Additionally, the implant 100 may include any appropriatedimensions, such as a selected length, width, height and depth. Further,the implant 100 may be formed to include an angle, such that a firstside of the implant 100 may be taller than a second side of the implant100. Regardless, the spinal implant 100 may be implanted into thecervical spine, such as to assist in fusing one or more cervicalvertebrae.

With reference to FIG. 10A and FIG. 10B, a lumbar spinal implant 120 forposterior lumbar interbody fusion (PLIF) is illustrated. The PLIFimplant 120 may be formed according to any appropriate dimensions. Forexample, the PLIF implant 120 may include a selected length, height,depth, or other appropriate dimensions. Further, as discussed above, thespinal implant 120 may be formed of the composite 20 or may be formed ofthe structure 10, and then filled with the selected polymer. Regardless,the PLIF implant 120 may be formed according to various specificationsfor a selected procedure.

Further, the PLIF implant 120 may include an exterior wall 122 that maydefine a structure including an interior wall 124 that defines anopening 126 that can be used to contain graft materials. The PLIFimplant 120 may therefore be formed to fit or be implanted into aselected portion of the anatomy, such as a spinal fusion procedure. ThePLIF implant 120 may be positioned in a selected portion of the spine,such as the thoracic portion, a lumbar portion, or a sacral portion,such as to assist in fusing one or more lumbar vertebrae. The PLIFimplant 120 may also include a grasping region 127. The grasping region127 may be defined as a groove or detent in the implant 120. Thegrasping region 127 may be grasped with an appropriate instrument, suchas a forked instrument, for positioning and holding the implant 120during implantation or other procedures.

With reference to FIG. 11, a spinal implant 150 for anterior lumbarinterbody fusion (ALIF) is illustrated. The ALIF implant 150 may includean exterior wall 152 and two interior portions 154 and 156. The firstinterior portion 154 may be defined by an interior wall 158. Similarly,the second interior area 156 may be defined by a second wall 160.Therefore, the ALIF implant 150 may include two interior voids oropenings 154, 156 for containing bone graft materials. Further, the ALIFimplant 150 may include a first side 162 that includes a height that isless than a second side 164. The height difference may provide the ALIFimplant 150 to be formed at a selected angle for various purposes. Forexample, the ALIF implant 150 may be positioned through an anteriorlumbar approach to assist in fusing one or more lumbar vertebrae.

Spinal implants, such as the implants 100, 120, and 150, or anyappropriate spinal implant may include selected materials to form theimplants. As discussed herein the materials may be selected for aselected strength or strength degradation. Also the materials for theimplant may be selected for a selected bone ingrowth.

With reference to FIG. 12, an implant 170 is illustrated. The implant170 may define a screw or anchor portion that may be positioned relativeto a selected portion of the anatomy. The implant 170 may define athread 172 that extends along a length of the implant 170 from a firstor insertion end 174 to a second or driving end 176. The thread 172 mayor may not extend the entire length of the implant 170.

Regardless, the implant 170 may define the thread 172 and the drivingportion 176 such that the implant 170 may be inserted into a selectedportion of the anatomy. Similar to the implants 70, 90 illustrated inFIGS. 7 and 8 above, the implant 170 may be used to fix a selected softtissue therein, fix a suture thereto, or other appropriate procedures.For example, in a generally known anterior cruciate ligamentreplacement, the implant 170 may define an interference screw to assistin holding the graft in a selected position.

The implant 170 may be formed substantially completely of the compositematerial 20. It will be understood that the implant 170 or the implantsdescribed above according to various embodiments, may be provided forvarious procedures or purposes. As is generally understood in the art, agraft may be positioned or provided of soft tissue to interconnect afemur and a tibia. The implant 170 may be used to substantially hold thesoft tissue portion relative to a selected portion of the anatomy. Asdiscussed above, the composite material forming the implant 170 may beabsorbed into the anatomy at a selected rate to allow for bone ingrowthand fixation, such as a generally anatomical fixation, of the softtissue may be provided.

With reference to FIG. 13, an implant 190 is illustrated. The implant190 may generally include or define a structure that is substantiallyplaner and includes a first surface 192 and a second surface opposedtherefrom. The implant 190 may include a selected thickness that issubstantially less than a surface area of the surface 192. Therefore,the implant 190 may generally be described as a plate or strut. Theimplant 190 may include any appropriate geometry such as a trapezoid,rectangle, square, or the like. Further, the implant 190 may definebores or holes 194. The bores 194 may be provided for various purposessuch as fixation with fixation members, including screws, pins, and thelike.

The implant 190 may be used for various purposes, such as fracturefixation, where the implant 190 may be used to stabilize bone fragmentsand to assist in healing of the fracture site. The implant 190 may alsobe used as a graft retaining plate or structural support during spinalfusion procedures. The implant 190 may be formed to include a selectedrigidity or strength, as discussed above, for assisting in the bonystructure healing. As previously discussed, the implant may or may notcontain polymer regions attached to the composite to improve the bendingresistance and rigidity of the device or to impart a polymer seam thatwould provide flexibility. For example, a support portion of the polymermaterial 21 may be placed or formed along a length or other dimension ofthe implant 90 to achieve a selected strength or other property.

Additionally, implant 190 in FIG. 13 may also be used for soft tissuefixation as a buttress plate. In soft tissue fixation procedures,sutures are often used to affix the tissue to bone. The thin crosssection of the suture, however, may not provide a selected result afterimplantation. The implant 190 may be used to assist sutures in achievinga selected result in various applications. The plate may provide asurface to abut the suture and protect other tissues, if appropriate.Therefore, a soft tissue implant may include a structure substantiallysimilar to the implant 190 illustrated in FIG. 13. Therefore, theimplant 190, according to various embodiments, may be used to repair aselected portion of soft tissue, such as a rotator cuff. The implant190, however, may be formed to repair any selected portion of the softtissue, such as a muscle portion, a tendon, a ligament, a dermalportion, or the like.

Similar to the plate 190 in FIG. 13, an implant 200 in FIG. 14 can beused for fracture repair. As discussed above, the implant 190 may beformed to allow for fixation or holding of selected bony portions duringa healing process. Other implant portions, such as the implant 200, mayalso be used to fix or hold selected bony portions at the fracturerepair site. The implant 200 may include an extended shaft that definesa thread 202 along all or a portion of the shaft. A driving portion 204may also be provided to assist in driving the implant 200 into theselected implant site. The thread 202 defined by the implant 200 may bedriven into a pre-formed bore, a tapped bore, an untapped bore, or anypredefined void. Further, the implant 200 may be formed in appropriatedimensions, such as a length, thickness, thread height, etc., to achieveselected results. The implant 200 may also be cannulated and have asimilar composition to the dual region devices 90 of FIG. 8.

With reference to FIG. 15, an implant 220 is illustrated. The implant220 may include a suture anchor or define a suture anchor to assist inholding a selected suture 222 used in soft tissue repair. For example,the suture 222 may be to reattach a soft tissue region to bone or othersoft tissue. The implant 220 may define a shaft or body including afirst end 224 and a second end 226. The body of the implant 220 mayfurther have a first engaging or interference portion 228 extendingtherefrom. Further, a second interference portion 230 may also beprovided.

The implant 220 may then be driven into the bone of the soft tissuefixation site. The suture 222 is then used to affix the soft tissue tobone. The implant 220 may be generally driven into a bore formed in theportion of the anatomy including a diameter less than a diameter ordimension of the interference members 228, 230. Therefore, the implant220 may form an interference fit with a selected portion of the anatomyto hold the suture 222 relative to the selected portion of the anatomy.

With reference to FIG. 16, an implant 250 is illustrated. The implant250 may include any appropriate configuration, for example, the implant250 may be formed as a wedge or triangle. Although exemplified as atriangle, the wedge may have any shape. The implant 250 may furtherdefine an interior void or open portion 258 for the containment of bonegraft materials. For example, as discussed herein, the open portion 258may be filled with a selected bone graft material, such as an autograftor allograft, or a porous bone growth scaffold for promoting bonehealing at the site.

With reference to implant 250, the device may be used in structuralgrafting applications in areas such as the foot and ankle, tibia, femur,and pelvis where structural support is desired in addition to boneregeneration. The implant 250 may be filled with a selected material 262that has been positioned in the open portion 258.

As illustrated above, the continuous phase composite material 20 may beformed in the plurality of configurations for various purposes. Further,as also discussed above, the structure 10 may be formed into a selectedshape, orientation, geometry, or the like and then filled with apolymer.

Similarly, it will be understood, that the final implant shape may beestablished inter-operatively to provide a custom fit to the surgicalsite. For example, the bone graft wedge of implant 250 illustrated inFIG. 16 may need to be augmented due to an anatomy of a patientdetermined during an operative procedure. Therefore, a user, such as asurgeon, may use powered surgical instruments such as a burrs, drills,osteotomes, grinders, or other tools to substantially customize theimplant for the selected patient. Therefore, the implant may be providedeither as a blank or in a general shape for eventual customization bythe user during a clinical procedure. This may assist in providing aselected result for a patient and decrease healing time, complications,or the like.

The implant 250, whether customized or not, may be used in a proceduresuch as to replace a selected portion of a bone 260. The implant may befilled with the graft material 262 to fill a void that may have formedin the bone 260. A further plate 266 (see FIG. 17) may also be used inthe procedure. However, the implant 250 may allow for a selected loadbearing for a selected period of time and allow for bone ingrowth intothe implant area.

With reference to FIG. 18, an implant 300 is illustrated. The implant300 may be used for a thoracic procedure, or any appropriate procedure.The implant 300 may include an exterior wall 302 and also a top portion304. The top portion 304 may also define teeth or other fixationportions 306 to assist in maintaining the implant 300 in a selectedposition. An interior wall 310 can also define an interior void 312. Theinterior void may allow for positioning of graft material during animplantation. The implant 300, however, may include any appropriatedimensions for a selected procedure. The implant 300 may be used as adisc replacement in a selected procedure, such as in a spinal fusionprocedure.

Therefore, it will be understood that the composite 20 illustrated inFIG. 3 may be used for any appropriate procedure. The materials chosento create the composite 20 may be selected from a range of biocompatibleand bioresorbable materials to give properties specific to the surgicalapplication. In addition, the fabrication of composite implants withpure polymer or ceramic regions may also provide specific propertiesbased on the application. The composite 20 may be formed into anyappropriate implant, such as a structural bone graft, a fixation device,an interbody spinal implant, a prosthesis, or any appropriate implant.Devices for cartilage, tendon, and ligament repair, vascular prostheses,tissue engineering devices, and other medical implants also fall withinscope of the continuous phase composite. Therefore, the examplesprovided above are merely exemplary and not intended to limit the scopeof the teachings herein.

Various different material combinations may be used to form thecomposite 20. The various different combinations of materials may beselected for different purposes and applications, such as where animplant may be positioned in the anatomy. For example, with reference toTable 1, different applications of the implant may include a differentselected property. The selected property may be formed or incorporatedinto the composite material from which an implant may be made dependingupon the combination of materials and selected materials used to formthe composite 20.

TABLE 1 Application Implant Type Selected Property Spinal FusionInterbody spacer Compressive strength, impact resistance Fracturefixation Fractures screws, pins, Torsion, bending, pull out rodsstrength Fracture fixation Fracture plates Bending, tension Soft tissuefixation Interference screws Torsion, pull out strength Soft tissuefixation Suture anchors Torsion, pull out strength Structural bonegrafts Bone graft wedges, Compression, impact bone graft containmentresistance devices

For example a procedure may be selected to include a selected property,such as a compressive strength after a selected time period afterimplantation. For example, a spinal fusion implant may be selected toinclude about 1500 N to about 3000 N of compressive strength at leastabout six months after implantation. This may be selected for variouspurposes, such as the amount of time generally necessary for boneingrowth to form a selected fusion. Therefore, a selected material maybe chosen for the polymer 21 of the composite 20. For example, thePLDLLA polymer, discussed above, may form about 60% of the composite 20with about 40% of the composite 20 being the structure 10 formed of thePro Osteon 500R. Such a combination can achieve a compressive strengthof about 1500 N to about 3000 N at about 6 months after implantation.Although other polymers and other structures 10 may be used to achievesimilar results.

In other applications, a fast resorption of the composite 20 may beselected. For example, in a fracture healing or repair may be fasterthan in a fusion. Therefore, an implant that is substantially resorbedafter about 3 to about 6 months may be selected. Such an implant may beformed with a copolymer of lactic acid and glycolic acid. The copolymercan be about 85% lactic acid and about 15% glycolic acid, similar to thematerial sold as Lacotsorb™ by Biomet, Inc. An implant including such acopolymer as about 60% of the composite while the other about 40% isformed of the Pro Osteon may be used in a fracture situation. Forexample, the screw 170 may be formed of such a composition for use in anAnterior Cruciate Ligament replacement procedure to provide a selectedtime when the graft is no longer held with the implant screw 170.

Also the polymer, or slower resorbing material, may be selected basedupon inherent properties or ones formed therein. For example, a slowerresorbing polymer may generally be one including a higher molecularweight. Thus, the slower the implant should resorb or the longer aselected property, such as compressive strength is needed, the higherthe molecular weight may be chosen for the polymer. However, it willalso be understood that selected polymers may include properties thatmay be achieved at lower molecular weights. Also selected strengths ofthe polymer may be inherent in the polymer itself, rather than aselected molecular weight thereof.

The composite 20 may be formed according to a plurality of methods, asdiscussed above. Although the composite may also be formed to include aselected material contained therein. As discussed above, graft materialmay be positioned in an implant formed of the composite 20.

With reference to FIG. 19, an implant 350 may be formed according to theillustrated method 351. A blank 356 may be formed of the structurematerial 10. The structure material 10 may be any appropriate porousmaterial, such as a polymer matrix, ceramic, or the like. The blank mayalso be shaped into any appropriate geometry, such as cylinder.

The blank 356 may then be injected with the polymer, as discussed above.This may create polymer portions 358 that extend from a composite 352,that may be similar to the composite 20. The injection may occur bymelting the polymer and injecting it under pressure into the poresand/or channels defined by the blank 356. The composite 352 may thenhave the exterior polymer portions 358 removed to include substantiallyonly the composite 352.

A fill material 354 may then be inserted into the composite form 352.The fill material 354 may be any appropriate material. For example thefill material 354 may be substantially similar to the material thatformed the blank 356. The two portions, including the fill 354 and thecomposite 352 may then be heated to meld the two together to form theimplant 350.

The implant 350 may be similar to the implant 250 that included thegraft material. In the implant 350, however, the fill material 354 maybe formed into the implant and provided complete for a procedure. Thus,implants may be formed to include voids or pre-filled voids. The fillmaterial 354 may serve the same purpose as the graft material discussedabove, such as a void filling or support purposes. Nevertheless, theimplant 350 may include the fill material 354 and be manufactured withthe fill material 354.

With reference to FIG. 20 a flowchart 400 of a method of forming animplant according to various embodiments is illustrated. The method 400may begin at a start block 401. Then a selected implant region isselected in block 402. The implant region may be any appropriate regionof the anatomy. For example, a spinal region, a tibial region, a femoralregion, a humeral region, or the like may be selected. As discussedabove implants may be formed for any appropriate portion of the anatomyusing the composite 20.

After the implant region is selected in block 402 loads may bedetermined relative to the region in block 404. For example, acompressive force, shear force, torsion force, or the like may bedetermined at the selected region of the anatomy. For example, it may bedetermined that about 1500-3000 N may be experienced in a spinal region.Although other forces may be determined and may depend upon a patient,the region selected, and other considerations.

Also other forces that the implant may experience can be determined. Forexample a torsion stress necessary for implantation may be determined.Thus not only forces in the selected region of the anatomy, but otherforces may be determined in block 404. Properties of an implant may thenbe determined in block 406. For example, after the experienced forcesare determined in block 404 the forces that the implant may be requiredto withstand, for various reasons, can be determined. For example, ifthe force experienced in the spine is about 1000 N it may be selected toform the implant to include a compressive strength of about 3000 N atabout 6 months after implantation. Therefore, the loads determined inthe anatomical region may be different than those determined as aproperty of the implant in block 406, but they may be related.

Also, a selected resorption time may be a property selected in block406. For example, a resorption time of the implant may depend uponselected loads in the region of the anatomy or ingrowth rates at theselected regions, or other selected reasons. Thus the resorption time orprofile of the implant may be determined in block 406. In this regard,bond ingrowth in various regions of the body may vary depending on theregion, loads encountered, and anatomical condition of the area ofinterest.

Then implant materials may be determined in block 408. The materialsselected may be the appropriate material to form the structure 10 or theappropriate polymer for the polymer fill 21. Although, as discussedabove, both can be polymers or both can be ceramic materials. Also, theimplant materials may be selected to achieve the selected properties,such as a strength, strength degradation profile, resorption profile,load bearing, etc. As also discussed above the materials selected may bea polymer of a selected molecular weight, a certain co-polymer, etc.

Also in determining the materials in block 408 the form of the implantcan be determined when determining the implant materials in block 408,or at any appropriate time. As discussed above the implant may include acomposite portion and a non-composite portion. Therefore, to achieve thedetermined properties of the implant, such designs may also bedetermined in block 408.

Then the implant can be formed in block 410. The implant may be formedof the materials determined in block 408 and the configurationdetermined in block 408. The implant may be formed according to anyappropriate method and the formation method may also be chosen dependingupon a selected property. For example, a polymer may be melted and theninjected into a porous structure. Nevertheless, any appropriate methodmay be used to form the implant in block 410.

The implant formed in block 410 may then be implanted in block 412. Asdiscussed above the implant may be customized by a user prior toimplantation or it may be implanted as formed in block 410. Also a graftmaterial may be used with the implant formed in block 410, also asdiscussed above. Generally, however, after the implant is formed inblock 410 it can be implanted in block 412. Then generally the methodends in block 414.

The method 400, however, is merely exemplary and an implant may beformed of the composite 20 according to any appropriate method. Theimplant formed according to method 400 can include a selected propertyto achieve selected results after implantation. The selected propertiescan be achieved by selecting appropriate materials for the compositeimplant, a selected configuration of the implant, or other appropriateconsiderations.

Also, regardless of the method chosen the composite may be used to forman implant that includes a selected strength over a selected period oftime, yet can still allow ingrowth of bone. The composite material maybe formed into an implant where bone may grow into regions that arefaster resorbing than other regions. This may be created by includingthe faster resorbing phase and the slower resorbing phase. Thedifference in resorption rates may be any appropriate difference, suchas about 10% to about 200% different. Regardless, the slower resorbingphase may be selected for a strength quality to achieve a selectedstrength degradation profile, while the faster responding phase may beselected based upon the bone regrowth rate of the area of interest. Thiscan assist in bone regrowth and in allowing recovery when a resorptionmay be selected in a load bearing area of the anatomy. This may also beused to achieve a selected strength of the implant for a selected periodfor any appropriate purpose.

As otherwise understood, the method 400 can be used to select materialsand properties of the materials for a selected or unique application.The known or determined bone growth rate of a selected region of theanatomy can be used to assist in determining the materials to be used informing the implant, the ratios of the materials to be used, or thespecific properties of the materials to be used. Also the forces thatare experienced in a selected region of the anatomy may be used toselect the materials to be used to form an implant. Thus a higherselected strength may be used to select different materials for formingthe implant. Therefore, the method 400 may be used to select materialsfor an implant, select a structure of an implant, or other features ofthe implant.

The teachings herein are merely exemplary in nature and, thus,variations that do not depart from the gist of the teachings areintended to be within the scope of the teachings. Such variations arenot to be regarded as a departure from the spirit and scope of theteachings.

1-42. (canceled)
 43. A resorbable implant, comprising: a single memberhaving: a continuous formation, having a plurality of continuouschannels forming a first and second sub-plurality of pores of a porousfirst material resorbable into an anatomy at a first rate to allow boneingrowth; and a second material for resorbing into an anatomy at asecond rate different than the first rate to support the bone ingrowth;wherein the first material and the second material are distinct andseparately combined into the single member by positioning the secondmaterial within a structure of the formation of the first material, soas to substantially fill at least a first sub-plurality of the pluralityof pores of the porous material.
 44. The resorbable implant of claim 43,wherein the first sub-plurality of the plurality of pores has amacroporosity of a first average size that is larger than the secondsub-plurality of the plurality of pores having a microporosity.
 45. Theresorbable implant of claim 43, wherein the member is a compositecomprising a porous matrix formed with the first material being anabsorbable ceramic and the second material being a polymer injected intothe first sub-plurality of pores in the porous matrix; wherein thesecond sub-plurality of pores allows fluids to flow into an interior ofthe member.
 46. The resorbable implant of claim 43, wherein the secondmaterial comprises a polymer comprising polylactic acids, polyglycolicacids, and combinations thereof.
 47. The resorbable implant of claim 45,wherein the porous matrix includes a structure of calcium carbonatedefining the plurality of pores; wherein inner walls of the firstsub-plurality of pores and the second sub-plurality of pores aresubstantially coated with a hydroxyapatite.
 48. The resorbable implantof claim 45, wherein the second sub-plurality of pores includes anaverage pore size of less than about 1 μm; wherein the fluids flowthrough the second sub-plurality of pores to allow a degradation of thecomposite when in an anatomy.
 49. The resorbable implant of claim 43,wherein the continuous channels extend from a first surface of thestructure to a second surface of the structure.
 50. The resorbableimplant of claim 43, wherein the single member includes about 55 wt % toabout 65 wt % of the second material.
 51. A single member resorbableimplant, comprising: a continuous formation of a first materialresorbable into an anatomy at a first rate to allow bone ingrowth,wherein the first material has a first plurality of channels having afirst average size and a second plurality of channels having a secondaverage size that is smaller than the first average size; and a secondmaterial for resorbing into an anatomy at a second rate different thanthe first rate to support the bone ingrowth; wherein the first materialand the second material are distinct and separately combined into thesingle member by positioning the second material within a structure ofthe formation of the first material.
 52. The single member resorbableimplant of claim 51, wherein the second material is positioned in thefirst plurality of channels.
 53. The single member resorbable implant ofclaim 52, wherein the second plurality of channels remain open.
 54. Thesingle member resorbable implant of claim 53, wherein the single memberis about 55 wt % to about 65 wt % of the second material.
 55. The singlemember resorbable implant of claim 53, wherein the second average sizeof the second plurality of channels is about 0.01 μm to about 1 μm. 56.The single member resorbable implant of claim 53, wherein the secondmaterial is a polymer comprising polylactic acids, polyglycolic acids,and combinations thereof.